Wooden mast

[hastan]

Hello everybody,

I am trying to start a new projet: I want to convert my old boat into a gaff rigg sailed boat.
I already have some good plans to do that but for the moment I have no idea which wood I can use to build my mast and all of the others (Bowsprit, Boom, etc... )
Lot of people suggested to use sitka spruce but it's a quite complicated to find and to much expensive for me.

Is there any other wood that can be used for a mast or boom ?
(my mast will be above 20 feets and 16 feets for the boom)

Thanks in advance for any information about this topic.

Regards,

Luc

[lupussonic]

Hi Hastan, welcome to the forum.

What is the hull? Originally a sailing hull? Got any pics?

Larch or Douglas fir might be alternatives for you. What type of spars? Solid or constructed?

[sailcanoefan]

I harvest a pine tree from a local forest, then shape it to fit my sailboat. Let it dry for a while and varnished.
Is there a local forest in your neighborhood???

White spruce is also good.

[wizbang 13]

Yes of course there are other woods you can use.
The versatility of a home made gaff rig is its greatest self fulfilling asset!
the rig can be made cheaply or expensive, simple or complicated.

[hastan]

Hi Hastan, welcome to the forum.
What is the hull? Originally a sailing hull? Got any pics?
Larch or Douglas fir might be alternatives for you. What type of spars? Solid or constructed?

Yes, my boat is an old Star class Sailboat ( http://www.starclass.org/index.shtml )


It's a racer but I really love the classicals lines and I really want to try to sail with a gaff rig boat.
So I decided to convert my boat into an Gaff rigg star class boat.
I already bought a plan from a well known traditional naval architect.


For the spars my first idea was to construct them with an hexagonal assembly.


There is different objectives for this project:
- I want want to understand and learn how traditional spars are builded
- I will also learn how to sewed my sails
- I will also build myself my pulleys\blocks
and then, learn to sail on a gaff rigg boat of course.


@Sailcanoefan: I am also near Montréal. Do you think that could be possible to meet you to speak about this project ?
@lupussonic: If I am using a Larch or douglas, do you know if it possible to find some long piece of wood or will I have to do some scrafs ?


ps: I apologize for my poor english. Sorry for that.

[wizbang 13]

I believe stars were originally gaff rigged, however, they would have been a lightweight "racer" gaff rig.
Something out of my area of knowledge.
A boat that is heavier , more robust, would make a better platform for you to learn with.
Retro rigging a Star is a job for someone who has done this once or twice already.

[Garret]

While no expert on mast building, I have looked for wood in the NE US (I'm about an hour & 15 min. from Montreal) & I think you will have a lot of trouble finding anything as long as 20 ft.

I'll toss out an ad I just saw on Vermont Craigs List for a 24 ft. mast (& a 2nd mizzen mast): https://vermont.craigslist.org/bpo/5980984356.html I have no connection, but it might be a place to start. He says he used white spruce. There is certainly plenty of that available in our area.

[BillyBudd]

For a different boat (Phil Bolger's Chebacco, a 20' cat yawl), I built all the spars out of Eastern Spruce. Got it from local sawmills at about US$.40/BDF. My spars are hollow except for the boom. The hollow spars meant that I cut out knots and wild grain and expoxied wood strips together with a long scarpf. The final result was clear spruce. Check out how to make "bird mouth hollow masts" on the Wooden Boat website, and be up to date on use of epoxy for boatbuilders. I kept all spars except the boom lightweight. For the boom I inserted a piece of 1/2" plywood as a flitch plate to help on stiffness. Where gaff, boom, cabin roof partners come onto the mast, I inserted wood stiffeners in the hollow, and I ran a 1/2" dia. plastic conduit pipe the full length of the mast for electric lines. After rounding I finished off the spars with UV resistant varnish which I renew yearly. Going on 10 years now and all work fine. Have a great time!

[sailcanoefan]

@Sailcanoefan: I am also near Montréal. Do you think that could be possible to meet you to speak about this project ?

Yes, I PM you.

[Rich Jones]

When I built my gaff-rigged sloop, I used clear Doug fir for the solid mast. I used Sitka spruce for the gaff and boom.

[stromborg]

Cool. That yard is peaked up so high it looks like a sloppy gunter!

I'd probably go with a douglas fir birdsmouth mast and probably yard too, but I don't know the dimensions.

[upchurchmr]

That yard is peaked up so high there is no real reason not to make it a Bermudian rig.

[Canoeyawl]

Cool. That yard is peaked up so high it looks like a sloppy gunter!

I'd probably go with a douglas fir birdsmouth mast and probably yard too, but I don't know the dimensions.

Eastern Spruce makes great small boat spars. *Note that L. Francis did a small boat design with a similar rig that used conventional sail track to attach the yard rather than the more traditional (clunky) jaws and parcels. I liked it...

[MN Dave]

Sitka spruce; perfect is the enemy of good?

If you aren't building an airplane or the ultimate racing machine, any good quality clear spruce picked from the pile at the local lumber yard will do nicely.

Sitka spruce has long been revered for having the highest strength to weight ratios. That is why it was used in the most critical applications, such as aircraft. Before we get too excited about the superlatives, we should look at how much higher the ratios are, and which ones are actually higher. I took numbers from the wood database and found that while the ratios for Sitka are the highest among the spruces, they are not much higher.

For the ratios, the strength numbers were divided by the average dried weight. The metric ratios were multiplied by 100 or 1000 to make them easier to read.

..	..	..	Sitka	spruce	..	White	spruce	..	Engleman	spruce	..	Douglas	-fir
Average Dried Weight:	lbs/ft3 (kg/m3)	..	27	425	..	27	425	..	24	385	..	32	510
Specific Gravity	(Basic, 12% MC)	..	0.36	0.42	..	0.33	0.43	..	0.33	0.39	..	0.45	0.51
Janka Hardness:	lbf (N)	..	510	2,270	..	480	2,140	..	390	1,740	..	620	2,760
Modulus of Rupture:	lbf/in2 (MPa)	..	10,150	70	..	8,640	59.6	..	9,010	62.2	..	12,500	86.2
Elastic Modulus:	lbf/in2 (GPa)	..	1,600,000	11.03	..	1,315,000	9.07	..	1,369,000	9.44	..	1,765,000	12.17
Crushing Strength:	lbf/in2 (MPa)	..	5,550	38.2	..	4,730	32.6	..	4,560	31.5	..	6,950	47.9
..	..	..	..	..	..	..	..	..	..	..	..	..	..
strength to weight ratios	Janka Hardness:	..	19	534	..	18	504	..	16	452	..	19	541
..	Modulus of Rupture:	..	376	165	..	320	140	..	375	162	..	391	169
..	Elastic Modulus:	..	59259	26	..	48704	21	..	57042	25	..	55156	24
..	Crushing Strength:	..	206	90	..	175	77	..	190	82	..	217	94
Shrinkage:	..	..	..	..	..	..	..	..	..	..	..	..	..
..	Radial:	..	4.30%	..	..	4.70%	..	..	3.80%	..	..	4.50%	..
..	Tangential:	..	7.50%	..	..	8.20%	..	..	7.10%	..	..	7.30%	..
..	Volumetric:	..	11.50%	..	..	13.70%	..	..	11.00%	..	..	11.60%	..
..	T/R Ratio:	..	1.7	..	..	1.7	..	..	1.9	..	..	1.6	..

You should be able to find 20' or longer dimension lumber. I would pick through the wider construction grade planks, looking for clear wood on one side or between the knots. You can often rip some good clear wood from one side and make some decent 2x4s from the rest. You pay a lot for clear wood, and you will be ripping long lengths anyway. The cost of the clear wood cut from lower grade stock may be lower, and the left over material still has value.

[John Husky]

I live in Montpelier. The local lumber yard, which is not a large chain store, was able to order vertical grain Doug Fir for me in long lengths. Mine were 20' x 2"x 4". It was dry and suitable for glue and varnish. That is what my mast and boom was made of. I'm sure 24' lengths would be reasonable. I don't expect it would be reasonable to bring lumber to Canada, but this stuff is coming from the Pacific Northwest so you should have easy access to it as well. Good luck.

[sailcanoefan]

Les Bois Malo, à Ste-Mélanie ont sûrement le bois, Douglas Fir.

[cejenkinsjr]

I built a solid mast for a Demon 15 out of Douglas Fir. I bought 6 eight foot 2 x 4's and epoxied them together and then power planed them down to round. This mast is almost 22 ft. I sailed it last summer. what a kick! I have a youtube video if you're interested. https://www.youtube.com/watch?v=14ppgHoVFxE

[Bob Cleek]

Cool. That yard is peaked up so high it looks like a sloppy gunter!

I'd probably go with a douglas fir birdsmouth mast and probably yard too, but I don't know the dimensions.

The gaff boom is peaked high like that so the boat will go to windward well. If less, she'd never sail anything like a Star. If you are going in that direction, I'd expect you will be better off with the lightest top-hamper you can achieve. You wouldn't want anymore weight aloft on a boat like that than you absolutely have to.

[Dan McCosh]

The Stars we have at the club have a modern rig notable for its complexity and lightness--they usually break at least once a year. The sail area combined with the light rig make them pretty interesting to sail. I don't quite get the gaff rig thing.

[hastan]

The Stars we have at the club have a modern rig notable for its complexity and lightness--they usually break at least once a year. The sail area combined with the light rig make them pretty interesting to sail. I don't quite get the gaff rig thing.

Yes I know that the modern rig is not exactly the strongest mast but this point is not part of motivation. In first I love all the gaff rigged boat and I really want to have the chance to learn how to build my spars and also being able to understand how the gaff rigg works.
And in my opinion, if I want to lean something... I just have to try

For the wood I will try to do some try with Douglas Fir.

Thanks everybody for all of your information.

For the beginning I will start with the Bowsprit.
I will let you know how this project will evolve !

Again thanks everybody.

[davebrown]

Birdsmouth hollow out of local spruce.